Switch x86/x86-64 -mtune from "atom" to more generic "intel"

-mtune=intel is tradeoff tuning between top IA archs whereas "atom" is
best on atom only.

Change-Id: I27668e4f48f26b00742d117a9a2a38e8903e22d5
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>
Remove libbfd.a build for host

Due to tricky configuration it cannot be build well when building 64-bit
targets. I didn't find any place in current AOSP tree where we are using
host libbfd.a so probably it's not required anymore?

build-host-gcc.sh doesn't build it either.

Change-Id: I9ed62c2d16bcb393e61bf913b6bab222bb783403
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>
Propagate -j in make calls for better parallelization

Also fix deps for parallel build.
It should speed up full NDK build.

Change-Id: Id62b4ba6b2d09fd28a2724c285eb0069b79b13fb
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>